A magnetic encoder device used for detecting the rotation speed (number of revolutions) of a rotary body is used for various purposes, and is composed of: a magnetic encoder including an annular fixing member for attachment to the rotary body, and an annular magnet member fixed to the annular fixing member and magnetized in a multipole form so as to have N poles and S poles at regular intervals in the circumferential direction; and a magnetic sensor which is attached to a non-rotary body so as to be opposed to the magnet member and which detects rotation of the magnet member.
Among such magnetic encoders, one of radial-type magnetic encoders for detecting the rotation speed (number of revolutions) of a rotary body in the radial direction is configured such that, for the purpose of cost reduction and the like, the magnet member is formed from a plastic magnet, the outer circumference of the fixing member (core) is formed to have an inclined surface, and the inner circumference of the plastic magnet (resin pulsar) is formed to have an inclined surface corresponding to the inclined surface of the fixing member (see, for example, Patent Literature 1).
In the radial-type magnetic encoder of Patent Literature 1, with an adhesive agent applied to both or one of the outer circumferential surface of the annular fixing member (core) and the inner circumferential surface of the annular plastic magnet (resin pulsar), the fixing member and the plastic magnet are moved relative to each other in the axial direction so as to be fitted to each other such that their inclined surfaces come into contact with each other, whereby they are integrated.